I have no motivation but don't think it's depression, worse since testosterone, synthroid (thyroxine) and untreated adrenal insuff. is antidepressants smart here?

Sleep study would be: Smart. Looking over the fact that you are 33 years old and lacking in testosterone, i suspect that you may have underlying sleep apnea that has caused your drop in motivation. Since sleep apnea is one of the few conditions that rather consistently lowers testosterone levels in young men, i would recommend that you have a sleep study done first. Your motivation should lift too without the need for any antidepressant treatment if my clinical hunch is correct. Please seek a sleep evaluation with a sleep specialist.

Maybe: It sounds like you have quite some endocrine deficiencies and low testosterone, cortisone, thyroid hormones can cause multiple mood symptoms and/or depression. You can wait until your hormone levels normalize and if you are not improved, recommend seeing mental health professional.

Possibly: You may find that treatment with antidepressants will be ineffective, if your medical issues are unresolved, and if they are contributing to your lack of motivation. I would suggest you address those first, if possible. It is also possible your low motivation stems from other factors, such as unresolved stress or life issues, and if that is the case, then therapy in addition to meds may help.